Method for producing artificial fibers from high molecular linear polymers or polycondensates respectively



Dem 1951 B. PILLER ET AL METHOD FOR PRODUCING ARTIFICIAL FIBERS FROM HIGH MOLECULAR LINEAR POLYMERS OR POLYCONDENSATES RESPECTIVELY Filed Sept. 21, 1949 7 travels through the extended difiusor.

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Patented Dec. 11,,1951

OFFICE METHOD FOR PRODUCING ARTIFICIAL FIBERS FROM HIGH MOLECULAR LINEAR POLYMERS OR POLYCONDEN- SATES RESPECTIVELY Bohumil Piller, Varnsdorf, Josef Zmatlik, Brunn, Jan Pinkava, Prague, and Miroslav Stary, Zilina, Czechoslovakia, assignors to Zavody pre Chemicku Vyrobu, narodny podnik, Bratislava, and Elite, sdruzene tovarny puncoch, nardoni podnik, Varnsdorf, Czechoslovakia Application September 21, 1949, Serial No. 116,992 In Czechoslovakia September 21, 1948 lt is well known to produce strong fibers by spinning molten linear polymers into a cool, nondissolving liquid medium, e. g. into water, or by cooling spun fibers a short time after having left the spinneret by bringing them into contact with a nondissolving liquid.

One device for said purpose forms object of copending patent application, Serial No. 96,593, now abandoned. It has been established however that polyamide or like fibers, which have not yet been oriented by cold drawing, became less strong when subjected for a long period of time to the influence of humidity. It is diflicult to carry out the further treatment immediately at any time, and the said circumstance makes the quality of produced artificial fibers uneven.

It has been found that the disadvantage mentioned above can be avoided and the quality of produced fibers furthermore amended if fresh spun fibers, cooled by a nondissolving liquid medium are rapidly dried, e. g. by means of a concurrent stream of a dry, heated gas or air respectively or in any other way before subjecting them to the linear orientation. It is then possible to store them dry for any desired time in unoriented state before the cold drawing and subsequent treatment. This method is especially suitable for fibers having normal or a very small diameter where the cold drawing resistance never surpasses the tensile strength of unoriented fiber.

A preferred method of drying spun cooled fibers consists in drawing off the spun and water cooled fiber or fiber bundle respectively from the take up roller or rollers by means of an ejector with an extended difiusor, said ejector being driven by hot air or gas, streaming with such a speed, that the fiber bundle is easily separated from the surface of the last take up roller without being oriented by stretching.

The temperature of air or gas respectively introduced into the said ejector is preferably chosen so high, that the fiber is dried in a very short period of time, durin which the fiber The fiber bundle is then coiled up in usual way and subsequently treated by cold drawing, twisting etc., which operations may be carried out in any desired succession.

It has been established, that the fibers spun in the way described above have a substantially increased tensile strength in comparison with not dried ones or with such fibers, which have not been cooled by means of water in the neighbourhood of the spinneret, but have been stored for a long time in a room containing water This effect is due to the fact, that no 6 Claims. ,(Cl. 18-54) hygroscopic dilution of the low molecular components with a superfluous swelling of the polymerized fibrous mass takes place, which circumstance usually makes the complete orientation of molecules in one direction and in optimal mutual distance uneasy or impossible.

One embodiment of the present invention is shown in the following example in regard to the accompanying diagrammatical drawing.

The fiber bundle is led from the spinneret over a grooved cylinder 2, concurrently with water running on its surface and then through a system of take up rollers 3 into the ejector 4. The inlet 5 is fed with nitrogen, preheated up to 200 C. under a starting pressure of 5 kg./cm. so that the gas speed in the diffusor 5 reaches several hundreds of m./sec. and gives to the fiber bundle the tension necessary for separating it from the take up rollers 3 without stretching it up to the linear orientation. The fiber bundle is then coiled up or treated in any other unshown way. The tensile strength of fibers, e. g. of those from polymerized G-caprolactam, scribed treatment from 5 g. up to 6.8 g./ den. The drying may be carried out in any other suitable way, e. g. by using radiant heat and, if desired, by simultaneously using reduced pressure.

We claim:

1. A method for producing artificial filaments from molten high molecular fiber-forming materials which are capable of being oriented by cold drawing, comprising the steps of spinning said material; cooling the thus spun material by bringing a. liquid into contact therewith; drying the thus cooled material; and cold drawing the thus dried material.

2. A method for producing artificial filaments from molten high molecular fiber-forming materials which are capable of being oriented by cold drawing, comprising the steps of spinning said material; cooling the thus spun material by bringing a non-solvent liquid into contact therewith; drying the thus cooled material; and cold drawing the thus dried material.

3. A method for producing artificial filaments from molten high molecular fiber-forming materials which are capable of being oriented by cold drawing, comprising the steps of spinning said material; cooling the thus spun material; drying the thus cooled material by means of an ejector provided with a long diffusor and fed with a heated gaseous medium, said gaseous medium streaming with such a speed that the material is moved through the ejector without being linearly oriented; and cold drawing the thus dried material.

increases by de- 4. A method for producing artificial filaments from molten high molecu1ar=fiber=io ming ma terials which are capable of being oriented by cold drawing, comprising the steps of spinning said material; cooling the thus spun material by bringing a liquid into contact therewith; drying the thus cooled material by means oi an ejector provided with a long difiusor, and fed with ,a heated gaseous medium, said gaseous-medium streaming with such a speed that the material is moved through the ejector without being linearly oriented; and cold drawing the thus dried material.

5. A method for producing artificial filaments said material; cooling the thus spun material joy from molten high molecular fiber-forming materielgwhich are capable-gt being oriented by cold drawin eor imthe. tepsspin i said material; cooling the thus spun material by bringing a non-solvent liquid into contact therewith passing the thus cooled material through a seto'r take rollers; then drying the thus cooled material by. means of an ejector provided with a long diiIusor and red with a heated gaseous medium, said gaseous medium streaming with such a speed that the material is moved through the ejector without being linearly oriented; and cold drawing the thus dried material.

BOHUMIL FILLER. JOSEF zMA'rLiK. JAN PINKAVA.

MIROSLAV s'rARY.

REFERENCES CITED The following references are of record in the file of this patent:

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1. A METHOD FOR PRODUCING ARTIFICIAL FILAMENTS FROM MOLETN HIGH MOLECULAR FIBER-FORMING MATERIALS WHICH ARE CAPABLE OF BEING ORIENTED BY COLD DRAWING, COMPRISING THE STEPS OF SPINNING SAID MATERIAL; COOLING THE THUS SPUN MATERIAL BY BRINGING A LIQUID INTO CONTACT THEREWITH; DRYING THE THUS COOLED MATERIAL; AND COLD DRAWING THE THUS DRIED MATERIAL. 